1. Field of the Invention
The present invention relates to cyclodextrin and, more specifically, to a process for removal of residual cyclodextrin from a system. The process of the present invention is especially applicable to food systems.
2. Description of Related Art
In recent years cyclodextrin has been used to remove unwanted substances such as cholesterol from eggs or butter; caffeine from tea and coffee; phenylalanine from protein hydrolysates; and phenolic compounds, pigments and bitter components from fruit juice. Typically, this removal process entails mixing cyclodextrin with a food system such that a complex forms with the unwanted substance and the cyclodextrin, and then removing the complex from the food system.
One of the problems associated with the use of cyclodextrin to remove unwanted substances from food systems is that not all of the cyclodextrin is removed from the system when the complex is separated from the system. It is known that the complexation process is an equilibrium reaction wherein an excess amount of cyclodextrin is added to the system to push the equilibrium toward complexation. This inevitably means that a certain amount of cyclodextrin is in the uncomplexed state when the complex is removed from the system.
Another source of uncomplexed or residual cyclodextrin left behind after removal of the complex is unremoved complex. In some food systems, for example coffee, the complex is removed as a precipitate from solution. Oftentimes soluble or readily suspendable complexes are not removed from the system. In other cases, such as butter, the complexes are removed by washing the butter with water. In these instances, not all of the complexes wash away. In either case, washing or precipitation, the residual complex goes through an equilibrium reaction wherein the guest and cyclodextrin move between a complexed and uncomplexed state.
It has been suggested that the residual cyclodextrin can be removed from the food system by incubating the food system with an alpha amylase derived from the microorganisms of the group Aspergillus niger, Aspergillus oryzae, Bacillus polymyxa, Bacillus coagulans, Flavobacterium, or domestic hog pancreas amylase, see U.S. Pat. No. 4,980,180.
A problem associated with some alpha amylases which have been used to hydrolyze cyclodextrin is that they do not hydrolyze all cyclodextrin. Specifically, it has been found that they do not hydrolyse branched cyclodextrin and they do not hydrolyze all of the alpha cyclodextrin. There is a need for a process which completely removes all residual cyclodextrin from a food system.